Last year, nearly 5.5 million Southern Californians participated. It is being expanded to northern California and has a goal of 10 million participants in 2009 making itÂ the largest earthquake drill ever.Â On the ShakeOut Twitter site, they announced a friendly competition between the two regions with SoCal ahead of NoCal by 1.8 million registrants.Â If you would like to participate, clickÂ here.